BOH Agenda 032520 - Laserfiche WebLink

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However, the other epidemiologic studies investigating relative contributions provide evidence favoring the pre-eruptive mechanism . Three such publications22-24 re -analyzed data from a single survey25 in which each child ' s periods of exposure - and non - exposure to fluoridated water were determined retrospectively . The re-analysis was restricted to first- permanent molars because they have an established chronology of crown mineralization during the first eight years of life , and because caries occurs most frequently in first molars . Residency in fluoridated areas during and after defined - periods of mineralization of first molars was used to classify exposure periods that plausibly are dominated by pre - or post- eruptive caries- preventive mechanisms . The analysis further investigated potential differences according to the anatomical location of caries on the tooth , and according to exposure during discrete phases of mineralization . The findings were consistent in showing that both pre- and post-eruptive mechanisms of caries prevention were necessary to explain observed caries preventive benefits of water fluoridation . Specifically : • Considering overall caries experience of first permanent molars, pre - eruption exposure was required for a caries- preventive effect whereas exposure only after eruption did not lower caries levels significantly; 23 • More detailed analysis of the period of pre - eruptive exposure showed that exposure during crown completion was important for caries prevention irrespective of the effect of exposure at crown maturation and at post- eruption , 24 • More detailed analysis of the anatomical location of dental caries found that, in surfaces with pits and fissure , greater pre -eruption exposure reduced caries levels significantly, whereas at other tooth surfaces, both high pre - and post-eruption exposure were required to prevent caries . z2 Another epidemiologic study designed specifically to test hypotheses about pre - and post- eruptive mechanisms was a cross-sectional study of n = 1, 485 South Korean children sampled either from an intervention community that ceased fluoridation seven years earlier or a comparison community that had never been fluoridated . 26 Among 11 year olds, caries experience was lower in the intervention community (where the children had been exposed to fluoridation for the first four years of life ) than in the control community . This was in contrast to equivalent levels of caries experience observed in the primary dentition , suggesting that the two communities had a similar risk for developing caries after cessation of fluoridation . The results in the permanent dentition are consistent with fluoridation in the intervention community producing a pre - eruptive effect that conferred caries - protection seen several years later, after the teeth erupted despite being unexposed to fluoridation after eruption . Another relevant consideration is the 2011 Cochrane systematic review of fluoride supplements . 27 It concluded that " use of fluoride supplements is associated with a reduction in caries increment when compared with no fluoride supplement in permanent teeth . " This is relevant because virtually all fluoride in fluoride supplements is swallowed , and because the recommended schedule is that they be discontinued within a few years after the permanent teeth first erupt . Hence, their observed caries preventive benefits must be due almost entirely due to pre - eruptive effects . Likewise , there is some evidence that fluoride supplementation of milk is effective in preventive caries, 28, 29 with studies suggesting that 3o both pre - and post- eruptive mechanisms account for the effect .